 Trade boomed, and relations with other countries likewise continued to be expanded.Though China accepted tributary missions from Hokuzan and Nanzan as well at this time, they officially recognized only the King of Chūzan as a head of state in Ryukyu.Chūzan continued to enjoy formal diplomatic relations with Ayutthaya and Korea, and trade relations with Java, Sumatra, and other states, as did the other two Ryukyuan kingdoms.